Incandescent lamp.



G. M. J. MACKAY. INGANDESCENT LAMP. APPLXCAHON FILED 020.20.1913. RENEWED MAR. 25. 1915.

L$3943 3 Patented Sept. 4, 1917.

Witnesses:

Inventor /;z 1 George filJmackag y/%%. e O

His fi'torneg" J. MAGILAY, (3F ISCHIENEGTAD'Z'. NEW "ZGRK, ASEIGNUR TO GEKE'JSDEMKL,

Exppiwtion filed Becembertlw, 3.913., iea'ial Ha. $367,817. Renewed March 25, mm. Serial No. @flfii-ifi.

To all whom i i m-ayaomem: 7

Be it known that l, GEORGE M. J. lfvllmlmy, a. subject of the living 0f Great Britain. rs siclimg at Schezmctady, county 0f Schenectsdy Stabs of ll ew Yarla, have invented eerwin. 119W and useful Improvements in 121' can lessens Lamps, 01f which the islluwing is aspscilicstisn.

llis present invention relates to the 0911'" smut oi the incandescent 306.31, 01' film 1mm, incandescent lamp, and pm'ticu-- m'ljy to tha type 0f lump in which a rsfrzw dsswnce, particularly in a. gas.

In accordancewiinli my invention. ment is shaped so as to-sscui's s. clssimii c istribution of tsmpsmsu-rswhich in gsnsral siwnid be substsnw'ially uniform ziizitn secure msciianiml stability of ills filsri'im'it when plislils as s high fismpermbui /Viilli.

. these smilsin visw, seotisms sf the filmnem;

subjscl $0 overheating and defer-mailer; by natural forces such as gravity 0 1 ills mag} DBlJRG held. of tli operating current am glvsn gl'eawer hast-dissipating esp-2mm Wilma fills lelnslxicisi 01 tile filament. .l snovsl few iii-gm]. or mercury vapor, so that the increase of light mm than offsets the increases? heat loss and a net gain 0f eliiciency is secured 'over operation in; an evacuated space. Tlis gaseous atmosphere. reduses the vaporization of the filament and also causes clspositimi of vaporized material at regions remote fmm. the filament, wlisis it will 110$, obseui's the light As explained more fully in Patent No. 1.180.159, issued L0 living Lnngnmir, the heat losses from; the filament in a. lamp of this character may be reduced by concentrat-Q ing the filimients m a giver; space, by culling them preferably in helical form.

My @XP'JIlKXlGBlES have shown that whgn sugipoiliecl at its ends by the filament is pliiibls While at ii mmmiescmlce the shape 91 the coil 91' helix may wry i1.'

regularly, smile of the turns hazing drawn tegethei' by magnetic attraction wild other turns 1M5 sax-bully rages. up by the wsiglil;

0f the remaining turns suspended llmmlzu.

thereby dsleteriuusly varying the lemmas I lamp which is emmonly of elongated shape.

Int-311i] l prefsgsl ly :mnsists. of malle'ablsfl tungsten. It 1s usually locatscl new: the,

lower part of tbs glass bulb film mamm- 01" otlieswlsecsnnectsd to cmi zluctm's 3,33 sealant m a glass stemfir welded, m.

will be noted le nit the lowermost ur'ns J l 01*. $13.91 filament am freely sussendsci as they 'suppcrtl' but their awn weiglifizl When phi-ibis; m. iizglz mszindescencs they mre spa; $50. bu.

drawn togethcr by the mz'agnetic fi ameof the heating currem, thereby, overheating this psrbof tile filmnent and eventually causing sllfil'ii-clfiiullllllg 0i parsuf the filmnenl; by

actual Contact of the; turns with. each other. The upper turns ot the helm receive heat by convexition GK'HTQIES from the lower puriof the. helix in'acldition to the heat electrically v developsd, and llencs this part of the lils znent will mud. to operate at an GXCUSSL'VB temperature.

in :wcordunce iviih my invention the 941-. gacent filament turns 'constitutmg the sem tion 01' ssztions which are to be given an increased heat dissipt-ing capacity, are spaced aparta greater distance tliai the turns c0nstitu 'cing i;l1e-renmi.n(ler of the, filament. v

In Figs. 2 and 3 the distances between the turns of tlishelix have beerl shown somewhatexaggerated. Ordinai'ily the clasely spaced turns are apart a space less Mum the dnuneter of the Ella-mania As shown 111 Fig. 2 the turns 6 it the sight of the filament 100p and-the.

upper turns are spread preferably by in- Sal'l'llflg spasms when the helix is prepam'sd, these, spacers being subsequently removed.

It is ordinarily unnecessary to spread Hie mg-11s 8 immediately adjoining tlle'supports, as heat is conducted away at'this rsgion by the suppm'ts. In some, instances, special provisicn may be made (70 prevent the cooling action of the leads by reducing'the crOss-ssc' liar; 0? tbs filsmenl in contact with the leacls.

In that event fewer turns maybe spaced close together near the point of contact ot the. filament with the support.

In some cases the spreading of the upper turns of thel h eli'x may be omitted as shown in. Fig. 'l'nithis clise the upper turns will sag somewhat after the lamp is running and thec'endle power of the lamp vary a corresponding extent. In some cases the spreading ofthe lower turns may be d'isplaced slightly upward, the very lowest turns being quite. close together and the turns next adjoining being opened up somewhat. In this the lowest turns are cooled by heat conduction through the wire to the adjoining region where greater heat dissipation occurs.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. An incandescent lamp comprising an envelop and a coiled filament therein suspended at the terminals only and having turns subject to overheating spaced more widely apart than the remaining turns.

2. An incandescent lamp containing a I freely suspended helical filament having a plurality of adjacent turns subject to def ormation by natural forces during operation and spaced apart more widely than other adjacent turns whereby substantially uniform incandescence during the life. of the lamp is secured.

'3. An incandescent lamp comprising an therein, a coiled tifngsten filament therein having turns most subject to distorting forces spaced apart a greater distance than other turns.

Anincandescent lamp comprising the combination of an envelop, a filling of inert gas thcreinand a helical refractory metal filament which is pliable at operating temperature of the lamp said filament having a? few of the lowermost turns and a plurality of the upper turns spaced apart a greate distance than other turns.

(3. An incandesecent lamp comprising the combination of an envelop a looped helically coiled filament Within said envelop and supports for the terminalsonly of said filament, the coils at the bight of said filament loop being spaced apart more widely than theadjacent coils.

7. An incandescent lamp comprising the combination of an envelop,'a filling of inert gas therein, and a helical filament therein supported at its terminals, the lowermost coils of said filament being at a greater distance from each other than the remaining coils.

In witness whereof, I have hereunto set my hand this 18th day of December, 1913.

GEORGE M. J. MACKAY.

Witnesses:

G. STANLEY MEIKLE, BENJAMIN 13.. HULL. 

